WO 2007/148263 A1 discloses a method for generating a set of kernels for convolution error compensation of a projection image of a physical object recorded by an imaging system like a computed tomography system. The set of kernels is calculated in such a way that for each pixel of the projection image an asymmetric scatter distribution for error compensation is calculated representing an X-ray scatter originating along a ray from an X-ray source to the pixel. The projection image is scatter corrected by performing a convolution error compensation using the generated set of kernels. If several projection images belonging to different angular positions of the radiation source are scatter corrected and if these scatter corrected projection image are used for reconstructing an image of the object, artifacts caused by scatter are reduced in the reconstructed image, thereby improving the quality of the reconstructed image.
But, if the set of kernels is used to perform convolution error compensation on detection values of a multi-energy computed tomography system, an image reconstructed by using the corrected detection values still comprises scatter artifacts caused by the spectral dependency of the scattering process.